Knife blade holders are well known and commonly used in ophthalmic surgery. The typical knife blade used in today's surgical procedures is usually constructed of diamond having a planar body with a cutting edge at one end. The blade is typically carried within a cylindrical housing with the cutting edge arranged so that it extends beyond one end of the cylindrical housing which has an opening to accommodate the blade. A mechanism is usually carried within the cylindrical housing and connected to the blade to permit axial movement of the blade with respect to the end of the cylindrical housing so that the blade can be totally withdrawn into the cylindrical housing when not in use and extended beyond the end thereof by a predetermined desired amount for use in surgical procedures.
For most ophthalmic surgical procedures, depth of incision is a critical factor in success of the procedure. The amount of extension of the cutting edge of the knife blade beyond the end of the cylindrical housing is a critical dimension for proper ophthalmic surgical procedures because it determines the depth of incision. Numerous devices have been developed and are in use to facilitate measuring the distance, and presetting the amount, of extension of the cutting edge of the knife blade beyond the open end of the cylindrical housing. One such device is illustrated and described in issued U.S. Pat. No. 4,662,075. In this prior art, the typical knife blade holder 14 carrying the knife blade 16 is illustrated. The device of this prior art provides a tray having a central groove 84 to support and accommodate the knife blade holder 16. The tray is moveable toward and away from a fixed plane, so that the blade holder can also be moved relative to the fixed plane. In this manner, the extension of the knife blade beyond the open end of the cylindrical housing can be set.
However, because the knife blade is planar, its cutting edge will also lie along a plane which must be properly oriented in the setting device in order to correctly adjust the extension of the blade beyond the end of the holder. The prior art holders do not provide any means to insure that the cutting edge will lie in a properly oriented plane (a vertical plane) when setting the edge extension.
It is accordingly a general object of the present invention to provide surgical knife blade holder and complimentary support tray to overcome the disadvantages of the prior art when setting the knife blade cutting edge.
It is also an object of the present invention to provide a knife blade holder which will insure proper alignment of the knife blade in a supporting tray when used to adjust and set the amount of extension of the knife blade cutting edge beyond the end of the cylindrical housing of the blade holder.
Another more specific object of the invention is to provide a knife blade holder which has means to orient the blade along the desired plane when placed in a blade setting device.
The above objects, features and advantages, along with other objects, features and advantages of the present invention will become more apparent from the detailed description of the invention in conjunction with the accompanying drawings to be described more fully hereinafter.